| 摘要 |
PURPOSE:To obtain the objective foamed particles having excellent weldability and giving low shrinkage after molding by using polyolefinic resin particles containing a specific amount of a quaternary ammonium salt, dispersing the resin particles in a dispersion medium in a closed vessel in the presence of carbon dioxide gas, heating the dispersion and discharging into a low-pressure zone. CONSTITUTION:Particles of a polyolefinic resin such as PP (the particle diameter is preferably 0.5-3mm) are dispersed in a dispersion medium in a closed vessel in the presence of carbon dioxide gas, heated at a temperature above the softening point of the resin particle and discharged into a low-pressure zone to obtain foamed particles. In the above process, the polyolefinic resin particle is incorporated with 0.1-5wt.% (preferably 0.1-1.0wt.%) of a quaternary ammonium salt such as octadecyl trimethyl ammonium salt. |
